Doorbuster sales seem to offer deals too good to be true.

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Standing in front of a 57-inch LCD marked "$500," the brain can get a little wobbly. This is what you read in the ad. It's real. It's right in front of you. It's too good to pass up. You want it, you need it, you look around desperately for someone to take your money and help you squeeze it into your car before that shifty-looking guy over there gets any closer.

Ah, the holiday doorbuster. The term dates back at least to 1935, indicating a really great sale price [source: Barrett]. These days, its meaning is more specific: This is a Black Friday sale price. The doorbuster deal has become a day-after-Thanksgiving tradition on the level of tummy aches and family staying a day or three too long. People wait in line for hours and hours to be the first in the store so they can snap up that $1,000 TV at 50 percent off.

Quantities, after all, are limited.

Why? Ostensibly because the prices are so insanely low that sellers are often losing money on those products. Sad for them, happy for you, right?

Not always. In the grand tradition of retail, all is not always as it seems, and the doorbuster is no exception. But really, $500 for that TV... How could that not be a beautiful thing?